Comparative Pharmacology
Head-to-head clinical analysis: DARVON N versus OXYCONTIN.
Head-to-head clinical analysis: DARVON N versus OXYCONTIN.
DARVON-N vs OXYCONTIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Propoxyphene is a weak mu-opioid receptor agonist that produces analgesia by binding to opioid receptors in the central nervous system, altering the perception of and response to pain. Its metabolite norpropoxyphene has local anesthetic and sodium channel blocking effects, which may contribute to cardiac toxicity.
Oxycodone is a full opioid agonist with relative selectivity for the mu-opioid receptor, although it can bind to other opioid receptors at higher doses. The principal therapeutic action of oxycodone is analgesia. Like all full opioid agonists, there is no ceiling effect for analgesia with oxycodone. Clinically, dosage is titrated to provide adequate analgesia and may be limited by adverse reactions, including respiratory and CNS depression.
100 mg orally every 4 hours as needed for pain; maximum 600 mg per day.
10 mg orally every 12 hours; titrate based on pain severity and prior opioid exposure.
None Documented
None Documented
Propoxyphene: 6-12 hours; norpropoxyphene: 30-36 hours. Accumulation of norpropoxyphene on repeated dosing increases risk of toxicity.
4.5-5.0 hours (immediate-release); controlled-release OXYCONTIN has an apparent half-life of 4.5-8.7 hours. Terminal half-life is ~3.5-4 hours for immediate-release, reflecting context-sensitive elimination.
Primarily renal (approximately 70% as unchanged drug and glucuronide conjugates); minor biliary/fecal elimination (25-30%).
Primarily renal (90% as metabolites, 10% unchanged). Also biliary/fecal (10%).
Category C
Category C
Opioid Analgesic
Opioid Analgesic